It is known in the art of conference calling to have a telephone with a speaker and a microphone integrated in the base of the phone for receiving audio from the surroundings and providing audio to the immediate surroundings, such as in a meeting room or an office environment. It is also known to provide a special conference calling hub connected to a standard phone for providing conference call functionality. Typically, the separate conference calling hubs will have a number of microphones and speakers distributed around the hub to obtain an improved reception of audio from the surroundings and further provide a better quality audio in multiple directions.
It is further disclosed in U.S. Pat. No. 7,110,789 to provide an interface from a conference calling hub to a cellular phone, so that the conference calling hub is connected to the wireless network when the cellular phone is engaged in the docking station or conference calling hub. The cellular phone may be controlled via the conference calling hub. The conference calling hub also comprises a handset which can be used in substitution of the microphone and the speaker in the cellular phone, when the cellular phone is engaged with the hub.
Such conference calling hubs are typically bulky and expensive and only provided in e.g. meeting rooms.
In U.S. Pat. No. 7,574,239, a docking station having passive components, such as speaker and microphone is disclosed. A headset communicating with a cellular or mobile telephone may be positioned in the docking station. When the headset is positioned in the docking station, the headset microphone and speaker are deactivated and the docking station microphone and speaker are used to communicate audio to and from a user. This is an advantage for use with e.g. a hands free operation of a car.
It is furthermore known to have a system of headsets with base units, wherein the base units are able to receive a number of headsets. Hereby, a number of users can connect to a current conversation by docking their headset in the base unit of the caller for a short time period (typically a few seconds) to establish a temporary pairing and connection to the callers' base unit. These users may then take part in the call through their own headsets.
However, it is a disadvantage of the above described systems that a base unit or conference calling hub is necessary for providing conference calling functionality for a headset, thus limiting the portability of the systems.